Polymeric film structures useful as shrink bags

ABSTRACT

The invention relates to heat shrinkage films having polyvinylidene chloride methyl acrylate blend as a barrier layer. Specifically, this invention relates to film structures having a first barrier layer comprising polyvinylidene chloride methyl acrylate blend wherein said barrier layer has two opposing surfaces; a second layer adhered to one of the surfaces of the first barrier layer comprising ethylene vinyl acetate copolymer blend; a third layer adhered to the other surface of the first barrier layer comprising an ethylene vinyl acetate copolymer blend; a fourth layer adhered to one of said second or said third layer comprising an ethylene acetate copolymer blend wherein the melt indexes of said blends of said second, third and fourth layers are the same; a fifth layer adhered to the other of said second or third layer comprising a blend of linear low density polyethylene and low density polyethylene. Said film structures have usefulness as shrink bags. Said film structure is oriented and may optionally be irradiated.

BACKGROUND OF THE INVENTION

Heat shrinkable polymer films have gained substantial acceptance for usein meat packaging. This description will detail the usage of films forpackaging meat, it being understood that these films are also suitablefor packaging other products. The films embodying this invention areuseful as heat shrinkable bags supplied to the meat packer with one openend, to be closed and sealed after insertion of the meat. After theproduct is inserted, air is normally evacuated, the open end of the bagis closed, such as by heat sealing, or applying a metal clip, andfinally heat is applied, such as by hot water, to initiate filmshrinkage about the meat.

In subsequent processing of the meat, the bag may be opened and the meatremoved for further cutting of the meat into user cuts, for retail sale,for example, or for institutional use.

Successful shrink bags must satisfy a multiplicity of requirementsimposed by both the bag producer and the bag user. Of primary importanceto the bag user is the capability of the bag to survive physicallyintact the process of being filled, evacuated, sealed closed, and heatshrunk. The bag must also be strong enough to survive the meat handlinginvolved in moving the contained meat, which may weigh 50 pounds ormore, along the distribution system to the next processor, or to theuser. Thus, the bag must physically protect the meat.

It is also highly desirable to the bag user that the bag serve as abarrier to infusion of gaseous materials from the surroundingenvironment. Of particular importance is provision of an effectivebarrier to infusion of oxygen, since oxygen is well known to causespoilage of meat.

The bag producer requires a product which can be produced competitivelywhile meeting the performance requirements of the user. Thus the bagmaterial should be readily extrudable, and susceptible to orientation,with sufficient leeway in process parameters as to allow for efficientfilm production. The process should also be susceptible to efficientextended production operations. In the orientation process, the filmmust be tough enough to withstand the stretching. The orientationtemperature should be a temperature which is economically achieved bythe producer, and which provides for use of economical shrink processesby the bag user.

Conventional shrink bags have generally been constructed with ethylenevinyl acetate copolymers (EVA). In some cases the bags contain a layerof a Saran copolymer to serve as an oxygen barrier. Ethylene vinylalcohol copolymer (EVOH) has also been suggested as the barrier layer.

Notwithstanding the advantages, shrink-bag packaging of meat is notwithout its difficulties, many of which are attributable to limitationsin the film. As will be appreciated, the processes of stretching thefilm, and later shrinking it, expose the film to rather severeconditions, due to the nature of the operations.

It is especially important to appreciate that the film is particularlyvulnerable to failure at conditions of operation, due to the relativelyhigh temperatures to which it is exposed in the orientation andshrinking process.

The film must be susceptible to orientation without distortion, orseparation of the multiple layers which are normally present in films ofthis nature. The film must be strong enough, at the orientationtemperature to withstand the stretching without creation of holes,tears, or non-uniform zones of stretching.

In the case of blown tubular film, the film must be capable ofsupporting the stretching bubble during the orientation process.Finally, each of the layers of the film should be susceptible toorientation without fracture, separation, or creation of holes in thelayer.

In packaging use, the film must respond to heat rapidly enough forcommercial practicability, and yet must not exhibit such a level ofshrink energy as would cause the film to pull apart or delaminate duringshrinkage, under its own internal forces.

In U.S. Pat. No. 4,457,960 oriented multiple layer polymeric filmscomprise a barrier layer having two opposing surfaces; a second layeradheres to one surface of the first layer, said second layer being 10%to 90% linear low density polyethylene and 90% to 10% ethylene vinylacetate copolymer; and a third layer adheres to the other surface of thefirst layer, the composition of said third layer being an ethylene vinylacetate or a blend of 10% to 90% linear low density polyethylene with90% to 10% of ethylene vinyl acetate. The '960 patent further disclosesa five layer film structure having a barrier layer; a second and thirdlayer having essentially the same composition and a fourth and fifthlayer having essentially the same composition with at least one of saidpairs having at least 50% of an ethylene vinyl acetate copolymer, theremainder being linear low density polyethylene and at least one of thepairs comprises at least 10% linear low density polyethylene, theremainder being ethylene vinyl acetate copolymer.

In U.S. Pat. No. 4,853,265 the heat-shrinkable, oriented, multi-layerpackaging film has at least two layers comprising an ethylene vinylacetate copolymer. One of the ethylene vinyl acetate copolymer layershas a melt index difference of about 0.3 dg/minute from the melt indexof the other ethylene vinyl acetate copolymer layer.

In U.S. Pat. No. 4,894,107 a process for making multiple layer polymericfilms is disclosed. The films have a layer of vinylidene chloridecopolymer between at least two other layers which contain ethylene vinylacetate and optionally, linear low density polyethylene.

In U.S. Pat. No. 5,030,511 films are made from vinylidene chloridecopolymer compositions comprising about 0.01% to 6% by weight of aprocessing aid wherein said processing aid has a molecular weight ofless than about 700. The films also have a first and second layerwherein each of the first and second layers comprises an ethylene vinylacetate copolymer having a melt index greater than about 1.2.

In U.S. Pat. No. 5,538,770 the polymeric film comprises first and secondsurface layers wherein said first and second surface comprise anolefinic polymer or copolymer and a vinylidene chloride polymeric layerdisposed between said first and second layers wherein said vinylidenechloride polymeric layer comprises 100 parts by weight of at least onevinylidene chloride copolymer; between 4 and 15 parts by weight of aplasticizer and between 4 and 15 parts by weight of an acrylate/styrenecopolymer.

Despite the known technology surrounding heat-shrinkable films, there isstill a need to improve the film in order to meet the demands of themeat packaging industry.

Thus, it is an object of the invention to provide improved filmstructures for use in shrink bags wherein the shrink bags are capable ofwithstanding production and shrink processes.

SUMMARY OF THE INVENTION

The present invention provides an oriented multiple layer polymeric filmuseful in the packaging of meat. The present invention also provides fora process for manufacturing the oriented multiple layer polymeric filmof the present invention. The present invention still further providesfor heat shrinkable bags which are made of the oriented multiple layerpolymeric film of the invention and are useful in the packaging of meat.

In one embodiment of the present invention the oriented multiple layerpolymeric film has a first barrier layer, the first layer having twoopposing surfaces; a second layer is adhered to one of the surfaces ofthe first layer; a third layer is adhered to the other surface of thefirst layer, a fourth layer is adhered to one of said second or saidthird layer; and a fifth layer is adhered to the other of said second orthird layer.

In this embodiment the barrier layer comprises a polyvinylidene chloridemethyl acrylate blend, the second and third layers independentlycomprise a blend of two ethylene vinyl copolymers wherein the melt indexof the blend for each of the second and third layers are the same; thefourth layer comprises a blend of two ethylene vinyl copolymers andprocessing additives wherein the melt index for the EVA blend of saidfourth layer is the same as the melt index for said second and thirdlayers; and the fifth layer comprises a blend of linear low densitypolyethylene (LLDPE) and low density polyethylene (LDPE).

A preferred embodiment of the present invention also has a first barrierlayer with two opposing surfaces, said first barrier layer comprising apolyvinylidene chloride methyl acrylate blend. A second and third layeradheres to the surfaces of said barrier layer comprising a blend of twodifferent ethylene vinyl acetate copolymers (EVA) wherein the melt indexfor the EVA blend of each second and third layer are the same; whereinfor each second and third layer one of the EVA is present in a range ofabout 65%-85%, preferably about 74%, based on the total weight of thelayer; the other EVA is present in a range of about 15%-35%, preferablyabout 26%, based on the total weight of the layer. A fourth layeradheres to one of said second or third layer comprising a blend of twodifferent EVAs and processing additives wherein the melt index for theEVA blend of said fourth layer is the same as the melt index for saidsecond and third layers, and wherein one of the EVAs of the blend ofEVAs is present at about 65%-85%, preferably about 72.5%, and the otherEVA is present at about 15-35%, preferably about 25% based on the totalweight of the layer, and the processing additives are present at about0.1-10% and preferably about 2.5%, based on the weight of the layer. Afifth layer adheres to the other of said second or third layercomprising a blend of LLDPE and LDPE wherein the LLDPE is present atabout 80-100%, and preferably about 90%, and the LDPE is present atabout 0-20%, and preferably about 10%, based on the total weight of thelayer.

A still further embodiment of the present invention has a first barrierlayer with two opposing surfaces comprising polyvinylidene chloridemethyl acrylate blend. A second and third layer adheres to the surfacesof said barrier layer each second or third layer comprising a blend oftwo different EVAs wherein the melt index for the EVA blend of eachsecond and third layers are the same with the understanding that one ofsaid second or third layer may contain additional processing additives.A fourth layer adheres to the surface of said second or said third layercontaining a blend of two different EVAs and processing additiveswherein the melt index for the EVA blend of said fourth layer is thesame as the melt index for said second and third layer. A fifth layeradheres to the layer of said second or said third layer containing onlya blend of two EVA and wherein said fifth layer comprises a blend ofLLDPE and LDPE.

A still further preferred embodiment of the present invention has afirst barrier layer with two opposing surfaces comprising polyvinylidenechloride methyl acrylate blend; a second and third layer adhere to thesurfaces of said barrier layer wherein one of said second or third layercomprises a blend of EVAs wherein one EVA is present at about 65-85%,preferably about 74%, and the other EVA is present at about 15-35%,preferably about 26%; the other of said second or third layer comprisesa blend of two different EVAs, and processing additives and wherein oneof the EVAs of the blend of EVAs is present at about 65%-85%, preferablyabout 72.5%, and the other EVA is present at about 15-35%, preferablyabout 25% based on the total weight of the layer, and the processingadditives are present at about 0.1-10% and preferably about 2.5%, basedon the weight of the layer; a fourth layer adheres to the surface ofsaid second or third layer containing a blend of two different EVAs andprocessing additives wherein said layer comprises a blend of twodifferent EVAs and processing additives wherein one EVA of the EVA blendis present at about 65-85%, preferably about 72.5%, and the other EVA ispresent at about 15-35%, preferably about 25%, and the processingadditives are present at about 0.5-10%, preferably about 2.5%; a fifthlayer adheres to the layer of said second or said third layer comprisinga blend of two different EVAs wherein said fifth layer comprises a blendof LLDPE and LDPE wherein the LLDPE is present at about 80-100%,preferably about 90% and the LDPE is present at about 0-20%, preferablyabout 10% based on the total weight of the layer.

In all the multiple layer films of this invention, the barrier layer ispreferably polyvinylidene chloride methyl acrylate blend. Other barrierresins such as polyvinyl chloride, ethylene vinyl alcohol copolymerwould also be suitable in the practice of this invention.

The films of this invention may optionally be subject to irradiationafter the completed fabrication of the multiple layer film structure butbefore or after orientation of said film structure.

Irradiation doses of from 2MR to about 10MR are used to irradiate thefilms of the present invention. A more preferred irradiation dose forthe films of the invention is from about 4MR to 6MR.

A substantial end use of the invention is in heat sealable shrink bagsfor utilization particularly in packaging of meat. Bags made accordingto the invention find particular utility in forming packages which aresubjected to low temperature shrinking processes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a bag made according to the invention

FIG. 2 is a cross-section of the bag of FIG. 1 showing a 5-layer bagstructure.

DETAILED DESCRIPTION OF THE INVENTION

It has been discovered that heat shrinkage bags comprised of the 5-layerfilm structures of the present invention possess improvements over knownshrink bag. These improvements are increased shrink at lower temperatureand improved coefficient of friction which results in an improved enduse due to the use of less starch.

FIG. 1 shows a bag made according to the invention. The empty bag shownis a collapsed, molecularly oriented tube with one end closed by a heatseal 2 across the one end of the tube. The other end of the bag is openfor the insertion of meat, and it is normally closed and sealed when themeat is put into the bag.

FIG. 2 shows a structure wherein the bag is made from a 5-layer filmstructure of the present invention. Layer 6 is the barrier layer whichminimizes the transmission of oxygen through the film. Layer 4 is theinner tie layer which serves to improve adhesion. Layer 8 is the outertie layer which serves to also improve adhesion. Layer 10 is the outerlayer which serves to protect the bag and its product from abuse. Layer2 is the heat sealant layer. It is to be noted that the components oflayer 4 and layer 8 contribute to the higher shrink at lower temperatureimprovement of the present film structure. In a preferred embodiment ofthe present invention layer 6 is 100% of polyvinylidene chloride methylacrylate blend; layer 4 is a blend of 74% of ethylene vinyl acetatecopolymer having an vinyl acetate content of 18% and a typical meltindex of 0.7 g/10 min and 26% of an ethylene vinyl acetate copolymerhaving a vinyl acetate content of 18% and a typical melt index of 2.1g/10 min. Layer 8 is identical to layer 4. Layer 10 is a blend of 72.5%of a ethylene vinyl acetate copolymer having a vinyl acetate content of18% and a typical melt index of 0.7 g/10 min and 25% of an ethylenevinyl acetate copolymer having a vinyl acetate content of 18% and atypical melt index of 2.1 g/10 min; layer 10 further comprises 1.5% of aslip processing aid and 1.0% of an antiblock. Layer 2 is a blend of 90%linear low density polyethylene and 10% low density polyethylene.

In another preferred embodiment of the present invention the barrierlayer is 100% polyvinylidene chloride methyl acrylate blend. The outertie layer is a blend of 72.5% of an ethylene vinyl acetate copolymerhaving a vinyl acetate content of 18% and a typical melt index of 0.7g/10 min; 26% of a ethylene vinyl acetate copolymer having a vinylacetate content of 18% and a typical melt index of 2.1 g/10 min, 1.5% ofa slip processing aid and 1.0% of an antiblock. The inner tie layer is ablend of 74% of an ethylene vinyl acetate copolymer having a vinylacetate content of 18% and a typical melt index of 0.7 g/10 min and aethylene vinyl acetate copolymer having a vinyl acetate content of 18%and a typical melt index of 2.1 g/10 min. The outer layer is identicalto the outer tie layer. The sealant layer is a blend of 90% linear lowdensity polyethylene and 10% low density polyethylene.

The overall thickness of films of this invention is nominally the sameas the thickness of conventional films. Films are generally about 2.0mils thick with a normal range of 1.5 to 3.0 mils. The individual layersof the film structure are in a range of 0.15 mils to 1.5 mils.

Ethylene vinyl acetate copolymers suitable for use in this invention arethose having an 18% vinyl acetate content and a typical melt index of0.7 g/10 min or a typical melt index of 2.1 g/10 min. Preferred ethylenevinyl acetate copolymers are manufactured by Exxon Chemical of Baytown,Tex.

These preferred ethylene vinyl acetate copolymers are exemplified byExxon LD-730.09 and Exxon LD-725.36.

A polyvinylidene chloride methyl acrylate blend suitable for use in thisinvention is exemplified by Dow Chemical Co. MA, Saran X U 30019.09.This particular vinylidene chloride, methyl acrylate copolymer comprise92.25 wt % of vinylidene chloride, 7.75 wt %, methyl acrylate; MW90,000-92,000; and 2 to 3% of processing aids such as stabilizers,plasticizers, and lubricants.

These processing aids may be exemplified by epoxidized compounds, suchas epoxidized linseed oil, epoxidized soybean oil,epichlorohydrin/bisphenol, epoxidized octyl tallate, epoxidized glycoldioleate, butyl ester of epoxidized linseed oil fatty acid, and thelike. Other suitable processing aids may include an additive such as2-ethyl hexyldiphenyl phosphate, tetrasodium pyrophosphate, oxidizedpolyethylene, antioxidant, magnesium oxide, or chlorinated polyethylene.

A linear low density polyethylene suitable for practice in thisinvention is exemplified by Dowlex 2247A-1 manufactured by Dow Plasticswhich is a business group of the Dow Chemical Company of Midland, Mich.

A low density polyethylene suitable for practice in this invention isQuantum NA 204-000 manufactured by the Millennium Petrochemicals ofCincinnati, Ohio.

A slip aid suitable for practice in this invention is exemplified by1080823 U Slip manufactured by Spectrum Colors of Minneapolis, Minn.

An antiblock suitable for practice in this invention is exemplified bySpectratech CM 12124 manufactured by Equistar Chemical Corporation ofCincinnati, Ohio and by Ampacet 10579 manufactured by AmpacetCorporation of Mount Vernon, N.Y.

The barrier layer for the film structure of the present invention ispreferably polyvinylidene chloride methyl acrylate blend. The barrierproperties of this particular copolymer are well documented in the art.The ethylene vinyl acetate blends for the various layers of filmstructures of the present invention provide manufacturingprocessability. The addition of an antiblock aid to the outer layer ofthe film structure for a preferred embodiment further enhances theprocessability of the film structure. While the individual components ofthe film structure each contribute their individualistic properties, itis the particular combination of these various components that providefor the superiority of the film structures of the present invention.

Definitions

As used herein, the following terms are understood to have the meaningprovided below:

“Polymer” means the product of polymerization and includes but is notlimited to homopolymers, monopolymers, copolymers, interpolymers,terpolymers, block copolymers, graft copolymers, and additioncopolymers.

“Processing aid” means a substance or material incorporated in a film orfilm layer to increase the flexibility, workability, or extrudability ofthe film. These substances include both monomeric plasticizers andpolymeric plasticizers and are generally those materials which functionby reducing the normal intermolecular forces in a resin thus permittingthe macromolecules to slide over one another more freely. The art refersto many plasticizers as stabilizers. Thus, the terms “plasticizer” and“stabilizer” are intended to be used interchangeably herein.

“Oriented” or “Orientation” refer to the process of stretching a hotplastic article followed by rapidly cooling while in the stretchedcondition to realign a molecular configuration thus improving mechanicalproperties. Stretching in one direction is called uniaxial orientationand in two directions is called biaxial orientation. In thermoplasticflexible films which have been oriented there is an internal stressremaining in the plastic sheet which can be relieved by reheating thesheet to a temperature above that at which it was oriented. The materialwill then tend to shrink back to the original dimensions it had beforeit was stretch oriented. Thus “oriented” flexible films are“heat-shrinkable” flexible films, and the terms “oriented” and“heat-shrinkable” are used interchangeably herein. For clarity, it isnoted that films made by a tubular process are referred to as having anorientation along the length of the tube, called the longitudinaldirection and/or across the width of the tube, called the transversedirection.

An “oriented” or “heat shrinkable” material is defined herein as amaterial which, when heated to an appropriate temperature above roomtemperatures (for example 96° C.), will have a free shrink of about 5%or greater in at least one linear direction, as per ASTM D 2732.

“Melt index”, abbreviated herein as MI, means melt flow measured at 190°C., 2.16 kilogram loading, as per ASTM D 1238, condition E.

As used herein the term “extrusion” or the term “extruding” is intendedto include coextrusion, extrusion coating, or combinations thereof,whether by tubular methods, planar methods, or combinations thereof.

As used herein the term two different ethylene vinyl acetate copolymersrefers to ethylene vinyl acetate copolymers having different meltindexes.

“Barrier” refers to a property in thermoplastic materials whichindicates that the particular material has a very low permeability togases, such as oxygen. The preferred barrier material referred to in thepresent invention is polyvinylidene chloride, methyl acrylate.

“Polyvinylidene chloride methyl acrylate blend” means that the blendcomprises ≈97% vinylidene chloride methyl acrylate copolymer and 2% to3% of processing aids.

The films described herein are capable of being manufactured accordingto conventional orientation processes. In the following example filmsare described in detail using equipment common to the “double bubble”process.

EXAMPLE 1

Example 1 is a film having a barrier layer of polyvinylidene chloridemethyl acrylate blend which is Dow Chemical MA. Saran X U 30019.9; anouter tie layer and an inner tie layer each having a blend of 74% ofExxon 730.09 and 26% of Exxon 725.36; an outer layer having a blend of72.5% of Exxon 730.09, 25% of Exxon 725.36, 1.5% of 108082 U Slip, and1.07% of Ampacet 10579, and an inner sealant layer having a blend of 90%of Dowlex 2247A-1 and 10% of Quantum NA 204-000. The polyvinylidenechloride methyl acrylate blend; the ethylene vinyl acetate copolymerblends; and the blend of linear low density polyethylene and low densitypolyethylene were plasticated and melt extruded through five separateextruders into a five-layer die and formed into a five layer tubularfilm on conventional “double bubble” equipment. The resulting film wasbiaxially oriented, with a stretch factor of approximately 2.5 in eachthe -machine direction and the 3.8 in the cross-machine direction. Theoriented film was 0.25 ml thick and was composed of 2.25 ml of sealantlayer; 1.05 ml of inner tie layer, 0.20 ml of outer tie layer, 0.55 l ofouter layer and 0.20 ml of barrier layer. The film structure of Example1 was irradiated at 4 to 4.6MR.

The film of EXAMPLE 1 was tested for free shrink at 180° F. and 200° F.using the following procedure:

Apparatus: Constant temperature bath—temperature of 30° to 150° C.includes temperature control, thermometer, and circulation pump. Similarto Fisher No. 13-874-115.

Forceps—similar to Fisher No. 10-316A.

Metric graphic paper, graduated in mm, enclosed in plastic.

Timer or wall clock. Similar to Fisher No. 6-658 (timer or 6-664(clock).

Wire gauze. Similar to Fisher No. 15-585B.

100 mm×100 mm template±0.5 mm.

Paper towels.

Razor blades—single edge safety.

Reagents: Tap water.

Safety: Caution: Avoid being burned by coming in contact with the shrinkbath.

Avoid careless handling of razor blades.

Sampling: Using the 100 mm×100 mm template:

Place the template in the center of the web parallel to the edge of thebag.

Cut around the outside of the template.

Retain the two samples, one each from the top and bottom position.

By cutting the sample 100 mm×100 mm, percent shrink in both directionscan be determined as a direct reading.

Mark the machine direction of each sample.

Procedure: Adjust the shrink bath temperature to 200° F.

Place the precut 100 mm×100 mm samples between two screens and immersein the bath.

Immersion time: 60 seconds

This time (6.2.1) allows sufficient time to complete shrink the film.Remove the sample from the bath and place on paper towel and pat dry.Measure the flattened film in mm in both directions.

Do not stretch the sample.

Calculations: Read the percent shrink directly from the graph papersince the initial measurement was 100 mm in both directions.

Read the percent growth directly from the graph paper if the film showsgrowth rather than shrink.

Report: Report the percent shrink or growth in both machine andtransverse directions.

Report the different in shrink or growth between the machine andtransverse directions.

References: ASTM Standard Method D-2838.

ACC Standard Method M-721. Fischer=Fischer Scientific Co.

A control bag which was manufactured based on the disclosure of U.S.Pat. No. 4,457,960 gave the following results in the above describedshrink test:

% Shrink in % Shrink in Cross Temperature Machine Direction MachineDirection 180% 23.5% 35% 200%   45% 54%

I claim:
 1. An oriented multiple layer polymer films structurecomprising: (a) a first barrier layer, said barrier layer having twoopposing surfaces; (b) a second layer adhered to one of said surfaces ofsaid barrier layer wherein the composition of said second layercomprises a blend of two ethylene vinyl acetate copolymers and whereinthe two ethylene vinyl acetate copolymers which comprise the blend ofthe second layer each have a vinyl acetate content of at least 18% anddifferent melt indexes; (c) a third layer adhered to the other surfaceof said barrier layer having the same composition as said second layer;(d) a fourth layer adhered to said second layers wherein the compositionof said fourth layer comprises a blend of two ethylene vinyl acetatecopolymers and processing additives and wherein the two ethylene vinylacetate copolymers which comprise the blend of the fourth layer eachhave a vinyl acetate content of at least 18% and different melt indexes;(e) a fifth layer adhered to said third layer wherein the composition ofsaid fifth layer comprises a blend of linear low density polyethyleneand low density polyethylene; wherein said second, third and fourthlayers have the same ethylene vinyl acetate (EVA) copolymer blend meltindex in cach layer.
 2. The film according to claim 1, wherein saidsecond layer may optionally contain a processing additive.
 3. The filmaccording to claim 1 wherein said barrier layer comprises polyvinylidenechloride methyl acrylate blend.
 4. An oriented film comprising: (a) afirst barrier layer wherein said barrier layer comprises apolyvinylidene chloride methyl acrylate blend and wherein said barrierlayer has two opposing surfaces; (b) a second layer wherein said secondlayer comprises a blend of two ethylene vinyl acetate copolymers whereinthe two ethylene vinyl acetate copolymers which comprise the blend ofthe second layer each have a vinyl acetate content of at least 18% anddifferent melt indexes and wherein said second layer is adhered to oneof said surfaces of said first barrier layer; (c) a third layer whereinsaid third layer comprises a blend of two ethylene vinyl acetatecopolymers wherein the two ethylene vinyl acetate copolymers whichcomprise the blend of the third layer each have a vinyl acetate contentof at least 18% and different melt indexes and wherein said third layeris adhered to the other surface of said barrier layer; (d) a fourthlayer wherein said fourth layer comprises a blend of two ethylene vinylacetate copolymers, wherein the two ethylene vinyl acetate copolymerswhich comprise the blend of the fourth layer each have a vinyl acetatecontent of at least 18% and different melt indexes, a slip additive andan antiblock additive and wherein said fourth layer is adhered to saidsecond layer; and (e) a fifth layer wherein said fifth layer comprises ablend of linear low density polyethylene and low density polyethyleneand wherein said fifth layer is adhered to said third layer; whereinsaid second, third and fourth layers have the same ethylene vinylacetate (EVA) copolymer blend melt index in each layer.
 5. The filmaccording to claim 4 wherein said ethylene vinyl acetate copolymer blendof said second layer comprises about 74% ethylene vinyl acetatecopolymer having a melt index of about 0.7 g/10 min and about 26% of anethylene vinyl acetate copolymer having a melt index of about 2.1 g/10min.
 6. The film according to claim 4 wherein said ethylene vinylacetate copolymer blend of said third layer comprise about 74% ofethylene vinyl acetate copolymer having a melt index of about 0.7 g/10min and about 26% of an ethylene vinyl acetate copolymer having a meltindex of about 2.1 g/10 min.
 7. The film according to claim 4 whereinsaid ethylene vinyl acetate copolymer blend of said fourth layercomprises about 72.5% of ethylene vinyl acetate copolymer having a meltindex of about 0.7 g/10 min and about 25% of an ethylene vinyl acetatecopolymer having a melt index of about 2.1 g/10 min.
 8. The filmaccording to claim 4 wherein said blend of linear low densitypolyethylene and low density polyethylene of said fifth layer comprisesabout 90% of linear low density polyethylene and about 10% of lowdensity polyethylene.
 9. A shrink bag made from the film of claim
 1. 10.A shrink bag made from the film of claim
 4. 11. A shrink bag made fromthe film of claim
 2. 12. The film of claim 1 wherein said film isirradiated.
 13. The film of claim 4 wherein said film is irradiated.